The invention relates to a method for sorting items provided with address information, in which the items successively pass through scanning means for generating a video image of each item, a mechanical storage track, and a printing station. In the known system, the video images are supplied to a first means for reading the address information and assigning a corresponding code. The items for which the address information can be read within a predetermined time are provided with the corresponding code in the printing station, and the video images of the items for which the address information cannot be automatically read within the predetermined time are supplied to video coding stations for reading the address information and assigning a corresponding code. The items that are not provided with a corresponding code are provided with an identification (ID) tag, and the code and ID tag are stored in order to provide the affected items with the code at a later point in time.
The invention further relates to a device for implementing the above described method, including means for scanning and generating a video image of each item, means for automatically reading the address information and for assigning a corresponding code to each video image, video coding stations for reading the address information and assigning a corresponding code to each video image, means for storing the video images and codes, a mechanical storage track, a printing station for characterizing items, and a control unit for controlling the above-named means and components.
In the last ten years tremendous progress has been evident in the development of mail-sorting facilities which has been due to the availability of economical and high-performance computing technology in the area of automatic reading of addresses. Despite this, however, up to now it has not been possible to read all letter addresses of postal items automatically or to automatically read them within a predetermined, acceptable time period. The letters that are not read automatically are either sorted manually or displayed on video displays at work stations, from which the postal code is typed while the letter is located in a mechanical storage track.
In so-called on-line video coding technology, video coding must be completed during the time in which the item is guided in the storage track. Usually only the postal code can be entered by video coding personnel, which permits sorting by primary directions, but not, however, by street and house number. Planning the number of operators proves difficult, because when reading rates, i.e. the proportion of mechanically readable addresses, fluctuate, the appropriate number of coding personnel must be available to enter the postal code manually. The integration of on-line video technology with devices for automatically reading the items, for example optical character recognition (OCR) technology, is already known. The crucial problems occurring in such integration result from the mechanical storage track, which determines how many items can be stored mechanically for further processing, and the non-homogeneous nature of the item flow, which results from the legibility of the addresses provided on the items.
To solve these problems, U.S. Pat. No. 4,992,649 discloses the characterization of each item with a code associated with the electronic or video image of the item. The characterization of each item is effected by applying a code or ID tag to the item that corresponds to the read address. In this known system, items that are not successfully read automatically are provided, in any case, with an ID tag and processed a second time, either by OCR reading electronics or manually by coding personnel at video coding stations. This so-called off-line processing is made possible by storage of video images of the items in an appropriate long-term memory. In this known system, information about letters that are not automatically readable is not lost, because the items receive an ID tag, thereby permitting the above-mentioned second processing of the video images. However, the drawback exists of non-optimum utilization of the option of processing items that are not automatically read and are still located in the storage track, whereby such items are not processed as quickly as possible by coding personnel at the video coding stations and provided with a code associated with the read address information.
Among codings, a distinction is further made between outgoing and incoming coding. In outgoing coding, the items leaving a post office are read and coded in particular according to the postal codes, whereas in incoming coding the incoming items are provided with a corresponding code depending on further components of the address information. In addition, methods of extraction coding, in which certain parts of the address are taken from the address and used in coding, are playing an increasingly important role. If coding takes place at video coding stations in the post office, or in the immediate vicinity thereof, in which the mechanical processing of the items is performed, the relevant coding technique is referred to as local; if, on the other hand, video coding takes place in a spatially separate coding center, the coding technique is called remote.